Estudio teórico y experimental de la polarización en FOP microestructuradas para su aplicación en sensado óptico

En este proyecto se presenta un estudio te orico y experimental de la polarizaci on de la luz en mPOFs cuando estas son sometidas a diferentes perturbaciones, para su aplicaci on en sensado optico

Estudio teórico y experimental de la polarización en FOP microestructuradas para su aplicación en sensado óptico

En este proyecto se presenta un estudio te orico y experimental de la polarizaci on de la luz en mPOFs cuando estas son sometidas a diferentes perturbaciones, para su aplicaci on en sensado optico

Accurate Strain Sensing Based On Super-Mode Interference In Strongly Coupled Multi-Core Optical Fibres

We report on the use of a multi-core fibre (MCF) comprising strongly-coupled cores for accurate strain sensing. Our MCF is designed to mode match a standard single mode optical fibre. This allows us to fabricate simple MCF interferometers whose interrogation is carried out with light sources, detectors and fibre components readily available from the optical communications tool box. Our MCF interferometers were used for sensing strain. The sensor calibration was carried out in a high-fidelity aerospace test laboratory. In addition, a packaged MCF interferometer was transferred into field trials to validate its performance under deployment conditions, specifically the sensors were installed in a historical iron bridge. Our results suggest that the MCF strain sensors here proposed are likely to reach the readiness level to compete with other mature sensor technologies, hence to find commercial application. An important advantage of our MCF interferometers is their capability to operate at very high temperatures.This work has been funded by the Fondo Europeo de Desarrollo Regional (FEDER); by the Ministerio de Economia y Competitividad under project TEC2015-638263-C03-1-R; by the Gobierno Vasco/Eusko Jaurlaritza under projects IT933-16 and ELKARTEK; and by the University of the Basque Country UPV/EHU under programme UFI11/16

Development of sensing technologies based on optical fibre from a new approach

53 p.En esta tesis doctoral se ha desarrollado una nueva tecnología para la fabricación de sensoresinterferométricos basados en fibra óptica monomodo estándar. Dichos sensores se caracterizan por ser detamaño micrométrico y de alta sensibilidad y resolución.Los dispositivos sensores desarrollados presentan dimensiones micrométricas, y están basados en unamicro-capa de polímero adherida al extremo de una fibra óptica monomodo. Dicha capa ofrece laposibilidad de controlar el patrón de interferencia en la fibra y, por lo tanto, su utilización en diferentesaplicaciones de sensado. Así, se han fabricado y evaluado experimentalmente diferentes muestras comosensores de temperatura, medidores de índice de refracción y sensores de humedad relativa. En los trescasos analizados, los resultados obtenidos han demostrado que, en cada prueba experimental realizada, elsensor proporcionó parámetros de velocidad de respuesta y resolución superiores a los ofrecidos por sushomólogos comerciales con los que se comparó.Además, se ha validado la posibilidad de fabricar dichos sensores de manera asequible y reproducible.Esta nueva tecnología de sensores basados en fibra óptica basados en interferometría resulta muyprometedora para el su empleo en aplicaciones de biosensado

Estudio teórico y experimental de la polarización en FOP microestructuradas para su aplicación en sensado óptico

En este proyecto se presenta un estudio te orico y experimental de la polarizaci on de la luz en mPOFs cuando estas son sometidas a diferentes perturbaciones, para su aplicaci on en sensado optico

Development of sensing technologies based on optical fibre from a new approach

53 p.En esta tesis doctoral se ha desarrollado una nueva tecnología para la fabricación de sensoresinterferométricos basados en fibra óptica monomodo estándar. Dichos sensores se caracterizan por ser detamaño micrométrico y de alta sensibilidad y resolución.Los dispositivos sensores desarrollados presentan dimensiones micrométricas, y están basados en unamicro-capa de polímero adherida al extremo de una fibra óptica monomodo. Dicha capa ofrece laposibilidad de controlar el patrón de interferencia en la fibra y, por lo tanto, su utilización en diferentesaplicaciones de sensado. Así, se han fabricado y evaluado experimentalmente diferentes muestras comosensores de temperatura, medidores de índice de refracción y sensores de humedad relativa. En los trescasos analizados, los resultados obtenidos han demostrado que, en cada prueba experimental realizada, elsensor proporcionó parámetros de velocidad de respuesta y resolución superiores a los ofrecidos por sushomólogos comerciales con los que se comparó.Además, se ha validado la posibilidad de fabricar dichos sensores de manera asequible y reproducible.Esta nueva tecnología de sensores basados en fibra óptica basados en interferometría resulta muyprometedora para el su empleo en aplicaciones de biosensado

Accurate microthermometer based on off center polymer caps onto optical fiber tips

We report on microscopic polymer spherical caps bonded onto the cleaved end of a single-mode fiber (SMF) for fast, accurate, and sensitive temperature sensing. The microcaps were fabricated by dispensing sub nano-liter amounts of UV-curable polymer onto the end face of a standard SMF that was cleaved at a small angle. A reflection from the SMF-polymer interface combined with a reflection from the polymer-external medium interface gives rise to a well-defined interference pattern. The high thermal expansion coefficient of the polymer used to build the micro-caps allowed us to achieve temperature sensitivity up to 270 pm/°C, resolution of 0.04 °C, and thermal response time of around 2.5 s. The simple fabrication process and the broad operating wavelength (from 800 to 1600 nm, approximately) of our devices along with the diversity of polymers currently available, make the concept and approach proposed here appealing for diverse sensing applications.This work has been funded in part by the Fondo Europeo de Desarrollo Regional (FEDER); by the Ministerio de Economía y Competitividad [TEC2015-638263-C03-1-R]; by the Gobierno Vasco/Eusko Jaurlaritza [IT933-16]; and ELKARTEK [KK-2016/0030, KK-2017/00033, KK- 2017/00089 and KK-2016/0059]. Oskar Arrizabalaga acknowledges a PhD fellowship from the Departamento de Educación, Política Lingüística y Cultura del Gobierno Vasco/Eusko Jaurlaritza

Miniature interferometric humidity sensor based on an off-center polymer cap onto optical fiber facet

In this work, we propose an interferometric humidity sensor based on a polymer micro-cap bonded off-center on the polished end of a standard single mode fiber (SMF). In our sensor, the sensitive part is the micro-cap. In the interferometer fabrication process, we can adjust the misalignment between the core and the micro-cap. It allowed us to control the visibility of the interference pattern. In our device, water molecules absorbed by the polymer microcap causes changes in the height of the microcap. This results in measurable shifts of the interference pattern. The fabricated samples were tested in a calibrated climatic chamber in the range from (similar to)10 to (similar to)95% of relative humidity (RH). The sensitivity and resolution of our device was found to be 148 pm per %RH and 0.04% RH, respectively. The obtained results suggest that our sensors can be useful to monitor relative humidity (RH) in miniature spaces.This work was funded by the Fondo Europeo de Desarrollo Regional (FEDER); the Ministerio de Economia y Competitividad (projects PGC2018-101997-B-I00 and RTI2018-094669-B-C31), and in part by the Gobierno Vasco/Eusko Jaurlaritza IT933-16 and ELKARTEK KK-2018/00078, (mu 4Indust and SMARTRESNAK). Oskar Arrizabalaga acknowledges a PhD fellowship from the Departamento de Educacion, Politica Linguistica y Cultura del Gobierno Vasco/Eusko Jaurlaritza

Study of the Influence of Various Stress-Based Mechanisms on Polarization of an SM mPOF for the Development of Useful Devices

In contrast to conventional polymer optical fibres (POFs), single-mode microstructured POFs (SM mPOF) exhibit polarization properties that make them potentially interesting for their use in the design and development of polarimetric fibre optic systems. In spite of the theoretical sixfold symmetry of the microstructure that yields zero linear birefringence, a measurement technique reveals us that the SM mPOF behaves as a linear birefringent system with clearly defined optical axes and characteristics. Regarding externally induced birefringence mechanisms acting upon the SM mPOF, either bend- and pressure-induced retardations or twist-induced light rotation follow the behaviour predicted theoretically. More specifically, bend-induced retardation varies linearly with the inverse square of the bending radius of the fibre, and in the case of asymmetrical lateral stress, pressure-induced retardation varies with the applied force. As to twist-induced rotation, the electric field rotates linearly with the angle through which the fibre is twisted. All cases are highly reproducible phenomena that, if used advantageously, may yield useful mPOF-based polarimetric optical devices not exploited yet.This work was supported in part by the European Regional Development Fund, in part by the Ministerio de Economia y Competitividad under Project TEC2015-638263-C03-1-R, and in part by the Eusko Jaurlaritza under Project IT933-16, Project ELKARTEK16/45, and Project ELKARTEK16/86. The work of M. Azkune was supported by a research fellowship from the University of the Basque Country (UPV/EHU), Vicerrectorado de Euskara y Plurilinguismo

1-42 beta-Amyloid peptide requires PDK1/nPKC/Rac 1 pathway to induce neuronal death

1-42 beta-Amyloid (A beta(1-42)) peptide is a key molecule involved in the development of Alzheimer's disease. Some of its effects are manifested at the neuronal morphological level. These morphological changes involve loss of neurites due to cytoskeleton alterations. However, the mechanism of A beta(1-42) peptide activation of the neurodegenerative program is still poorly understood. Here, A beta(1-42) peptide-induced transduction of cellular death signals through the phosphatidylinositol 3-kinase (PI3K)/phosphoinositol- dependent kinase (PDK)/novel protein kinase C (nPKC)/Rac 1 axis is described. Furthermore, pharmacological inhibition of PDK1 and nPKC activities blocks Rac 1 activation and neuronal cell death. Our results provide insights into an unsuspected connection between PDK1, nPKCs and Rac 1 in the same signal-transduction pathway and points out nPKCs and Rac 1 as potential therapeutic targets to block the toxic effects of A beta(1-42) peptide in neurons.LM was supported by the Sara Borrell program from the Carlos III Health Institute (Spanish Ministry of Science and Innovation, CD06/00275). MHR was supported by the Programa IKERTU, Department of Industry of the Basque Country Government, and JLZ was supported by grants from the Spanish Ministry of Science and Innovation (CIT-300000-2008-8), Department of Industry of the Basque Country Government (S-PE11UN018) and University of the Basque Country (EHU11/08 and UFI 11/20). We are grateful to SGIKer (UPV/EHU) for the technical and human support provided